Recovery of ingredients of waste lead-battery paste



Patented-Dec. 14,1926.

UNITED STATES PAT ENTO F- Ei I ALEXANDER STEWART, OF ROSELLE, JEB SEY, ASSIGNOB TO-C. L. CONSTANT COMPANY, OF HOBOIKEN, NEW JERSEY, Al CORPORATION OF NEWJERSEY.

jancovnnx or mennnmnrs of mm LEAD-BATTERY Plasma.

No brewing.

The. invention relates to a noyel method of treating the waste parts of lead battery plates to recover therefrom the valuable metal ingredients suchas lead and; antimony, the same being recoverable in various forms depending on the particular variation in the method ofitreatment employed. As generally obtained, ordinary waste battery paste com rises lead peroxide (PbO lead sulphate. PbSO and small amounts of antimony, usually from to 3%; together with foreign organic matter scrap battery plates, being separated from the plates and then treated in bulk in manner hereinafter set forth to obtain from same, in pure form, lead sulphate or other suitable salts of the lead content and antimony chloride or-other salt ofantimony.

To this ,end,-the invention comprises an' initial fusion of the waste paste material with an excess ofithesulphate of an alkali metal, preferably an acid salt, for example, nitre cake (NaHSO which 4 has been Four parts by weight of the paste material may be melted with three parts by weight of the-nitre cake, the operation being carried on at a dull red heat or approximately 200 0. above the fusion temperature of-the reagent. The fusion may be carried on in a suitable fur'nace,; crucible orf pot (not shown) and the paste may be mixed with the sulphate reagent either before the intro-- ductidn thereof'into the furnace or after the sulphate salt has first been fused. The fusion is continued until all the lead present is ing place-being substantially as followsfree oxygen is driven off, and the organic matter oxidized and consumed;

. After the fusion has continued sufliciently long, to convert all the marina a sulphate,

6 the fused. massis poured, in molten condition, 'into'a cold aqueous solution of a mixture of a sulphate of an alkalimeta-l, preferablyan acid salt, and a suitable chloride as sodium chloride or hydrochloric acid; or, the'fused mass maybe spray-cooled by well Application filed October 10', 1925. Serial Ro..61,837.

known methods, in which case-the resulting powder product is to be treated in a hot solution of the sulphate and the sodium chloride and must be maintained sufliciently hot" and thoroughly agitated so that the water will dissolve all of the normal alkali sulphate which was formed by the fusion as well as-to convert .all ofithe a timony (after fusion in the form of a sulp ate) to asolu ble chloride, the reactions being substan- I haiye found thatwith'5OO lbs. oi the acid 'sulp ate and 200 to 400 lbs. ofthe sodium chloride to a ton of water all of the antim'ony will be converted to the chloride and that practically none of the leadsulphate will go into solution. It is, -fi1 rthermore,z

desirable to thoroughly agitate'the mixture plished by'injec'ting steam. therein, as is well understood. i After the reactionshave been fully accom 75, of' the}- fused material with the aforesaid solution and this -imay'readil.'y be accom plished,-tlie agitation is stbppedand the leadsulphate is allowed to settle, whereupon the supernatant, liquor is decanted;- This liquor contains the-major'fportion of the antimony which was-contained in the aste,

the ame being in the form of the ch oride (81) l,,)'; and from which metallic antitreatments, such as precipitation upon metallic iron or by treatment sulphuretted hydrogen or an alkaline =,8111Pl11d9.

The lead sulphate remaining are, re, converted into'a sulphate, the reactions tak-f inoval of the solution by decantation' is to be thoroughly washed a number of times, pre-j mony may be recovered by;any. of the usual re-soluti'on of the lead sulphate and, second- I ly, 'reprecipitation of any residual antimony as oxychlorida; It is desirable inthe washings for elimination of sulphate salts and antimony, that vall solutions be kept:'as'hot as p/pssible until the washing is oreover, in the f from any res'idualantimony, it is found that freeing of'the lead phatem I atmes the operation isfasslsted by the 7 addition to the washysolution of 3% of one of the'followingeompounds: glucose, sugar, 1

glycerine. tartaric acid or citric acid. "It

will he understood, of course, that the use of PbSO, moo, Paolo Na,SO,.

Thelead carbonate is allowed to settle and the supernatant liquor then decanted, whereupon the residue may be washed a number of times by decantation, using small amounts of ammoniumcarbonateto'displace an alkaline salts which'may adhere-to the car onate 01 lead. After filtering and drying by any of the usual methods, the lead salt is ready for the market, or may be further converted into litharge, red lead or any other desired lead salt by any of the usual recesses in common use. It isto be noted, a o, that in the treatment with a carbonate such impurities assilica, arid with the sulphate of an alkali metal such impurities as copper, iron tin, magan ese, etc. which may have originally been 'resent with, the waste lead paste, are to a rge degree if not entirely ehminated and a par ticularly pure lead product obtained 1. The metlllllofih 0 IBtB ltiad bat- Haste w c P Q ejsame with an acid saltof iii alkali me 2. The method of waste lead bat-- tery paste, which comprises fusing the same with sodium acid sulphate.

3. The method of treating waste lead'battel-y paste, which comprises fusing four parts of the paste with three parts of acid sodium sulphate at a dulI red heat.

4. The method of treating waste lead'battery paste, which comprises fusing four parts of the paste with three parts of acid sodium sulphate at a dull red heat, and then treating the mass with an aqueous solution of a sulphate of an alkali metal and a chloride of a metal that does not form an insoluble sulphate.

5. The method of treating waste lead battery paste, which comprises fusing the same with a sulphate of an'alkali metal and dis charging the'molten mass into a cold aqueous solution of sodium acid sulphate and sodium chloride. l

' 6. The method of treating wasteleadbattery paste, which comprises fusing the samewith a sulphate of an alkali metal,discha'rging the molten mass into a cold aqueous solution oi? sodium acid sulphate and. sodium chloride, decanting the supernatant liquor.

and washing the residue to free the same from any residual antimony.-

7 In the treatment of waste lead battery -paste,.the method of separating antimony rom. the lead, which comprises treating a phate of the latter with an aqheous solution of a sulphate 10f an alkali metal and a' chloride 'ofa metal that does not form an insoluble sulphate.

18, In the treatment of waste lead battery aste, the method of separatingantimony rom'the lead, which compr' s treating a sislphate of the latter with a solution of soum acid sulphate and sodium chloride.

' In testimony whereof I afiix my slgnature.

- J ALEXANDER STEWART. 

